Wide plank boards (wider than 3¼″) are desirable in the hardwood flooring market because they show more wooden characteristics. The wide plank floor boards have been accepted as high end products and having a high value because they are made from a very limited resource, namely trees with a large diameter, and the production process has a low yield (only a small port of trees can offer large width boards). The wide plank floor board installation is also faster because it reduces the number of nails needed for an average square foot during the installation and thus saves installation time.
Wide plank hardwood floors, however, often experience dimensional instability, which is caused by its dimension, more specifically, its width, which varies as the moisture and temperature of the environment change. As season changes and air conditioner or heater is used, the indoor moisture and temperature change and consequently cause the moisture level in hardwood floor boards to change. Variation in the moisture level in the hardwood floor boards causes stress inside each hardwood floor board, which lead to wrapping, cupping, or popping up or shrinking after the installation. As the result, the hardwood floor shows gaps between the floor boards or bumps on the hardwood floor.
Wide hardwood flooring boards may shrink or expand before they arrive at the installation site. Shrinking and expansion changes the floor board's width and makes installation difficult. Thus the stability of hardwood floor boards (wider than 3¼″) is especially important to installation and maintenance of a hardwood floor. For this reason, hardwood floor boards, especially oak floor boards, are often processed to a width between 2.25″ and 3.25″.
It has been a major goal for hardwood flooring manufacturers to create a wide plank with less tree resource and with more stability. The traditional engineered hardwood uses layers of hardwood veneer to create a floor board, and these veneer layers are stacked on top of each other with the wood grain in one layer oriented perpendicular to the wood grain of another layer. Once the desired thickness is achieved, the boards are then cut into the correct board width. From there, the boards are then manufactured to have a tongue or groove on the edges. By doing this, the engineered hardwood floor board becomes less susceptible to the variation of moisture and temperature, because wood expands and contracts in the direction of the wood grain. Therefore engineered hardwood floor board is referred to as being dimensionally stable.
This traditional engineered floor board improves the stability to some degree, but it does not offer improvement under extreme dry or flood situations. As the air humidity falls very low, such as below 30-35%, the engineered floor boards are likely to delaminate because shrinking of wood layers causes stress and tears some layers inside of multilayer boards. During a flooding of short duration, multilayer floor board is not strong enough to remain stable and consequently floor board warps or cups.
Most of the traditional engineered floor boards used glue for tying down because the body of a multilayer boar is not strong enough to grip the nails. A traditional engineered floor board contains a high amount of glue in its body, which also has a high level of formaldehyde. The price of traditional engineered floor boards increases as their thickness increases. A traditionally engineer floor board is also lighter than a solid hardwood floor board, and this weight factor is perceived as having a low value in the market place.
Therefore, there is a need for floor boards that have a solid wood appearance and are water resistance, and it is to such floor boars the present invention is primarily directed to.